Volcanic Features:
* Lava Flows: The plateau is covered by extensive lava flows, some reaching thicknesses of hundreds of feet. These flows create flat, smooth plains and rolling hills.
* Canyons: Erosion by rivers has cut through the lava flows, creating deep canyons like the Columbia River Gorge and the Snake River Canyon.
* Buttes and Mesas: Isolated hills, often capped by resistant rock layers, rise from the plateau surface. These include the iconic Horse Heaven Hills in Washington.
* Calderas: Large, volcanic depressions like the Crater Lake caldera in Oregon are evidence of ancient volcanic eruptions.
Other Landforms:
* Palouse Hills: In the eastern part of the plateau, rolling hills formed by wind-blown loess (fine sediment) create a unique landscape.
* Dry Falls: A massive, dry waterfall in Washington state is a remnant of a catastrophic flood that occurred at the end of the last ice age.
* Glaciated Valleys: Portions of the plateau were affected by glaciers during the Pleistocene epoch, leaving behind U-shaped valleys and moraines.
* Wind-Sculpted Formations: Wind erosion has shaped some unique features on the plateau, including hoodoos and yardangs.
Specific Examples:
* Mount Hood (Oregon): An active stratovolcano and the highest peak in the Cascade Range.
* Mount St. Helens (Washington): Famous for its 1980 eruption, it is a stratovolcano with a distinctive crater.
* The Dalles (Oregon): A narrow gorge carved by the Columbia River through basalt cliffs.
* Hells Canyon (Idaho/Oregon): The deepest river canyon in North America, carved by the Snake River.
The Columbia Plateau is a region with a rich geological history and a diverse landscape, offering a fascinating study of volcanic and erosional processes.
